Aqueous functional fluids have, especially in recent years, gained substantial commercial important because of their well known economic, safety and environmental advantages over non-aqueous functional fluids, as well as their improved performance characteristics. These aqueous functional fluids have found significant usage as metal working fluids in a large variety of metal working processes (e.g. forming, grinding, drilling, broaching, milling, drawing and turning) and as hydraulic fluids.
Although aqueous functional fluids have been found to possess a number of advantages, they continue to show significant problems which limit their usefulness and usage. Chief among the problems presented by the use of aqueous functional fluids is the problem of corrosion control and prevention. This problem of corrosion control and prevention is particularly accentuated where the aqueous functional fluid contacts ferrous metals, although various degrees of corrosion may also occur where the aqueous functional fluid contacts non-ferrous metals (e.g. aluminum and copper). In metal working processes such corrosion leads to excessive wear of machine tool components and poorly finished products, while in hydraulic systems such corrosion leads to the destruction of pump components, valves and lines. Thus, corrosion inhibition becomes an important factor in aqueous functional fluids and such fluids having a high degree of corrosion inhibiting activity without sacrifice of the fluids' primary functions are therefore highly desirable. Strong corrosion inhibiting activity in aqueous functional fluids is continuously sought in the art.
Instability during storage and use is another problem often possessed by aqueous functional fluids. Such instability may lead to separation of the components, deterioration of the components and loss of the principle functions of the aqueous functional fluid. Where separation of the components of the fluid occurs, uneven concentrations of the components results and erractic, poor performance of the aqueous functional fluid is obtained. The art therefore continuously seeks to overcome such stability problems and provide (1) improved aqueous functional fluids having a high degree of stability and (2) materials which impart a high degree of stability to such fluids.
It is an object of this invention to provide an aqueous functional fluid having a high degree of corrosion inhibiting activity.
Another object of this invention is to provide an aqueous functional fluid having a component which imparts both stability and a corrosion inhibiting activity to the fluid.